Question

【题目】______ produced by qualified manufacturers, the vaccines were not transported in approved conditions.

A. As B. Since C. Though D. Before

Answer 1

【答案】C

【解析】考查连词用法 句意：尽管是具有资质的生产商所生产，但是那些疫苗并没有在适合的条件下运输。前后句子之间表示让步关系，故选C适合。